Scientists have discovered that elevated cholesterol levels may be related to various diseases, including coronary heart disease. However, studies have indicated that an individual's high-density lipoprotein (HDL) cholesterol level is inversely proportional to his risk of coronary heart disease.
Responding to the suggested link between cholesterol level and heart disease, many individuals began requesting blood tests to determine baseline levels and changes in their cholesterol levels. Scientists created tests to determine total cholesterol levels, as well as individual concentrations of low-density lipoprotein (LDL), very low-density lipoprotein (VLDL) and HDL cholesterol.
Prior art techniques for measuring HDL cholesterol levels involving selective precipitation, electrophoresis, or ultracentrifugation have several disadvantages. Prior art methods require pretreatment of the blood sample, addition of various reagents at different stages in the test process, and centrifugation or electrophoretic separation, and subsequent color development, or ultracentrifugation and subsequent visualization.
Due to the time required by these additional steps, HDL cholesterol analysis heretofore has not been automated like other blood tests. Therefore, the original blood sample must be separated into more than one aliquot, or more than one sample must be taken from each individual in order to perform any group of test procedures that include HDL cholesterol analysis. As a result, current techniques for determining HDL cholesterol levels are complicated, slow and labor-intensive.